Ladle-crane.



W. H. MORGAN.

LADLE CRANE.

APPLICATION FILED MAY 6. 1915.

Patented May 2, 1916.

2 SHEETS-SHEET I.

w. H. MORGAN.

' Patented May 2, 19116.

2 SHEETS-SHEET 2v WILLIAM HENRY MORGAN, OF ALLIANCE, OHIO.

LADLE CRANE.

Specification of Letters Patent.

Patented May a, rare.

Application filed May 6, 1915. Serial No. 26,382.

To all whom it may concern:

Be it known that I, WILLIAM HENRY' MORGAN, a citizen of the United States, and a resident ofAlliance, in the county of Stark and State of Ohio, have invented. certain new and useful Improvements in Ladle-Cranes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in ladle cranes and particularly to the trolley carrying two connected drums andtwo connected motors foractuating the drums, the object being to provide safety devices, by which if either of the motors-be out of commission or any of its gears be broken, the remaining motor can temporarily handle' the entire load and lower a ladle of molten metal should such an accident occur with the load suspended.

lVith this object in view, my invention consists in the parts and combination of parts as will be more fully explained andpointed out in the claims. i

In the accompanying drawings, Figure 1 is a view in plan of my improvement; Fig. 2 is view in side elevation of same; Fig; 3 is a view in section of one of the mechanical brakes and a part of'its shaft; Fig. 4 is a view of the worm.

1 represents the trolley frame, rectangula! in shape and mounted on the grooved wheels 3, which travels on a track on the crane bridge (not shown) in the usual and well known manner.

4 is the traverse motor of the trolley, secured to one of the main girders of the frame, and geared up to the shaft 5 which transmits motion to the grooved track wheels 3, at the ends of the trolley frame through the gear wheels (5, 7, 8 and 9.

10 and 11 are the main hoisting drumsjournaled in hearings on the trolley frame, with their ropes 12 leading down from the opposite sides of the two drums as shown in Fig. 2, the said ropes carrying sheaves from which the ladle carrying bar (not shown) is suspended. The drum 10 is provided at one end with a rim gear 10, and the drum 11 is provided with a similar gear 11 which meshes with gear 10, so that the two drums rotate simultaneously. Gear 10 meshes with small gear 14 on shaft 15 which carries the larger gear 16, which in turn is in meshwiththe smaller gear 17 that is con:- nected up w th the mechanical brake 18. The bore of gear'wheel 17 is internally threaded to engage'external threads 19 on wheels 14"- 16 17*21 and 22 and the shafts '15 and -20.

Each motor 23 and 24 is provided with an electro-magnetic brake. These'brakes form no. part of this invention, but as they are used as a precautionary or safety measure, I have represented the brake wheel of each by 25 and the electro-magnets by 26. These magnets are wired up in series with the motors 23 and 24 and are arranged so that should the current to the motors fail from any cause, the current in the magnets will be interrupted and the brakes set, thus locking the motors. Each gear train is also provided with two mechanical brakes 18 of the type shown in U. S. Patent 971,937 granted on the shafts 20 and 20 and each of the latter is provided with a threaded section 19 to be engaged by the internal threads on the gear wheels 17 and 17 respectively. As the two brakes are alike only one will be described, but-it should be understood that the mechanical brake is used on each shaft 20 and 20. I

Each brake consists of a sleeve keyed to its shaft and provided at its inner end with a disk 29 carrying friction blocks 30, the sleeve 28 beino mounted in a hearing 31 carried by the trolley frame. mounted on the shaft 20 and within the hearing 31 is the sleeve 32 having rigid connection with the gear wheel 17 so as to move longitudinally on the shaft, with the same, and it is provided with a disk 32 car rying the friction blocks 33.

Located intermediate the friction disks 29 and 32 and the friction blocks carried by the latter, is the friction wheel 34, mounted on the shaft but not keyed to the same. This wheel is provided on its periphery with teeth 35 which .engage the threads of worm 36, which as shown in Fig. 3, is disposed obliquely to wheel 34:. This Loosely v elevates and rotates the worm. The worm:

is mounted on ashaft carried by the casing and .may have an anti-friction bearing 36 at its top to take the end thrust of the worm while the friction wheel is turning in a direction to hoist the load. The teeth on thefriction wheel 34 and thread on the worm, are so constructed thatthey are always in contact, consequently all movements of the friction wheel are responded to instantly by the worm. When therefore the hoisting power is withdrawn, the shaft20 stops and the load carried bythe shaft tends torotate the latterin a direction to lower the load,

and as the friction wheel 34' will then be.

clamped between the friction disks 29 and 32 as will be hereinafter explained, the' said wheel 34 tends to turn in the reverse direction or in the direction to lower the load. This tendency, or, rather the very slight movement of the brake wheel 34 in the reverse direction, acting against the worm, forces the latter downwardly, thus bringing its conical section 36 into contact with the conical seat 36 in the worm casing and locks the worm against rotation, and

consequentlylocks the brake wheel against rotation inthe direction of rotation of the shaft 20 while lowering the load. The worm and wheel are always in contact, and as the longitudinal movement of the worm is very slight, it follows that the braking effect is instantaneous, thus preventing any reverse movement of the hoist drum and consequent strain on the ropes carrying the load.

It will'also be seen that when shaft 20 is at rest with a load thereon, the weight of the I load acting on the gear 17 turns the latter on the threaded section of the shaft,. and this longitudinal movement of the gear is imparted to the disk 32*, thus forcing the friction blocks 33 into contact with the wheel 34-and the latter into contact with friction blocks 30 on disk 29; and as the wheel 34 is held against reverse movement by the worm, it follows that further rotation of the gear 17 is prevented. The weight of the load always holds the wheel 34 clamped between the friction disks, and the separation of thefriction disks from the wheel, in lowering is just sufficient to permit them to rotate when the wheel 34 is held against movement, hence while there is a slight rotary and longitudinal movement of the gear 17 on its shaft, it is really negligible, or imperceptible to the eye.

It will be apparent from the foregoing, that with the load suspended and the shaft movement by the worm.

20 at rest, the weight of the load is transmitted directly to the brake, and as the wheel 34 of the latter is positively locked against rotation in the direction to lower the load, the parts will be held against movement, to lower the load. To lower the load the direction of rotation of the hoist .motor and shaft 20 is reversed. This movement of the shaft 20 causes the threads thereon acting on the internal threads of gear 17, to move the latter and its connected disk longitudinally away from wheel 34 thus relieving the friction of the disks against the wheel and permitting the disks to turn with the shaft, the wheel 34 being held against As soon as the friction is released the gear tends to race. under the influence of the load, but the instant the gear 17 begins to rotate faster than the shaft 20, the intermeshing threads on said parts move the gear toward the brake wheel 24 thus applylng the brake. These "movements of the gear 17 and disk 32" are in rapid succession and practically continuous hence are'not noticeable to the eye.

As there are two main hoists which are connected mechanically by the gears 10 and 11, it--follows that if any of the gears between either mechanical brake and its drum should break, the motor on the other hoist train would be able to temporarily handle the entire load and lower a ladle of molten metal, should such accident occur with the load suspended.

With the construction thus far described, should either of the two motors be out of commission and unable to operate, and its magnetic brake consequently applied, the load would lock the corresponding mechanical brake and thus tend to hold the entire gear train from revolving in the lowering direction. If the active motor were started in the lowering direction, it would be opposed by the brakes on the opposite train of gears and damage would result somewhere in the hoisting mechanism. In other words if the drum gear 10 were held stationary, and gear 11 operating in the hoisting direction, the latter would have a tendency to rotate around gear 10 and pull the drum shaft loose from its bearings, but if motor 24.were operating in the lowering direction the tendency would be to lift pinion 10 out of its bearings. If it were not for the mechanical brake'such a condition could be avoided by cross connecting the magnetic brakes on the hoist motors, that is to say, by wiring the brake of each motor in series with the other motor, so that should either motor be put out of commission, the brake on the opposite motor could be applied and both hoists would be prevented from operating until the motor was repaired. The fact that there is a mechanical brake included in each train of gears 1,1s1,1ta

changes the conditions entirely, as it is evident that should either motor stop from any cause, the tendency of the load acting against the mechanical brake, in addition to the power exerted by the active motor, would be to tighten the brake up and hold it until it is released by its motor. The only way to avoid the locking of the mechanical brakes, is to connect the two trains of gearing mechanically at some point between the motor and the mechanical brake, so that the operation of either motor would not only unlock its own mechanical brake, but would also unlock the mechanical brake on the opposite train, or in other words drive the opposite motor in the same direction as the active motor is operating and cause both motors to rotate at the same speed. This I have accomplished by means of the cross shaft 37 preferably made in two sections to facilitate handling, connected by coupling 38 at the center, each section carrying a miter gear 39 which meshes with similar gears 40 on shafts 20 and 20*. This cross shaft is supportcdin bearings 41 on the trolley frame. With such construction it will be seen that the two shafts 20'and 2O are positively geared together intermediate the drums, so that if one motar and its gearing remain in commission, the driven shaft (20,01 20) of the other motor can be positively rotated by the active motor. This arrangement enables either one of two connected hoist motors to handle the load on the trolley should the other motor for any reason be out of commission, or should any gear break except the drum gears, or any shaft break except shafts 20 or 20. The motors are designed for handling considerable overloads for brief periods, and hence either one could handle the entire load in an emergency.

It is evident that many slight changes might be resorted to in the relative arrangement of parts shown and described without departing from the spirit and scope of my invention. Hence I would'have ituhderstood that I do not wish to confine myself what I claim as new and desire to secure by Letters-Patent, is

1. In hoist mechanism, the combination of two drums, gear wheels connecting the same, an independent motor and gearing for each drum, a mechanical brake. forming a part of each motor gearing and gearing connecting the gearing of the two motors at a point between each motor and the mechanical brake of the other motor gearing.

2. In hoist mechanism, the combination of two drums connected to rotate in unison, a motor and gearing for each drum, a mechanical brake on a shaft of each motor gearing, and gearing connecting the said shafts, whereby the movement of one is imparted to the other.

3. In hoist mechanism, the combination of two drums having intermeshing gearing, a motor and gearing for each drum, and gearing independent of the intermeshing gearing on the drums, connecting the gearing of the two motors whereby the movements of each motor is transmitted to the other.

42. In hoist mechanism the combination of two drums having inter-meshing gearing, a

motor and gearing for each drum, a 'mechanical brake on a shaft of each motor gearing and gearing connecting the said shafts.

5. In hoist mechanism, the combination of two drums to rotate in unison, a motor and gearing for each drum, a mechanical brake on a shaft of each motor gearing, and a shaft and gearing connecting the shafts carrying the mechanical brakes.

6. In hoist mechanism, the combination of two drums connected to rotate in unison, a motor and gearing for each drum, a mechanical brake on a shaft of each motor gearing and a sectional shaft and gearing connecting the shafts carrying the mechanical brakes.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

WILLIAM HENRY MORGAN.

Witnesses:

WILLIS I-I. RAMsEY, N. C. I nrrnns. 

